chore(package): update mocha to version 6.1.1

Closes #36

Author: greenkeeper[bot]

package.json

@@ -49,7 +49,7 @@
     "json-schema-faker": "^0.4.1",
     "json-server": "^0.10.0",
     "localtunnel": "^1.8.2",
-    "mocha": "^3.2.0",
+    "mocha": "^6.1.1",
     "nock": "9.0.13",
     "npm-run-all": "^4.0.2",
     "nsp": "^2.6.3",